People often bond with strangers over the books they read or the movies they watch and build friendships that last. Scientists may now have some insight into why this happens. A study published in Nature Human Behaviour found that participants who responded similarly to the same movie clips even before meeting were more likely to become friends later.

As part of the experiment, MRI brain scans were taken of 41 graduate students who had never met each other before, while they were shown clips of movies based on science, food, sports, environment, and social events.

A total of 214 brain regions were analyzed—200 cortical regions associated with functions, such as movement, perception, and sensory processing, and 14 subcortical regions that control movement, autonomic functions, and emotions.